The present invention relates to animal litters. More particularly it relates to clumpable cat litters which are environmentally friendly, moisture absorbent and odor retaining.
Cat litter boxes are typically provided with an absorbent material that collects pet urine and feces. House pets are trained to leave their waste in these boxes, and periodically the pet owner throws away and replaces used litter.
Clay is often used as a litter box absorbent material. However, obtaining clay can be environmentally destructive, and in any event some clays contain materials that cause health concerns and/or clog household plumbing. Thus, ingredients such as ground corncob have been proposed as the absorbent material for cat litter.
Regardless of the nature of the absorbent material, a particularly desirable form of cat litter includes one or more ingredients that cause the litter to clump around wetted litter, permitting the used portion of the litter to be removed with a rake while the unused litter remains in the litter box. This helps reduce the incidence of mold growing in the litter box, reduces malodors associated with litter boxes, and avoids waste of unused absorbent material. For example, U.S. Pat. No. 6,053,125 teaches the use of ground corncob for kitty litter with guar gum as an additive to provide clumping capability.
However, there is still a need to address odor control. A variety of odor control materials have therefore been proposed to be added to cat litters. These range from masking fragrances to chemicals that suppress the vapor pressure of malodors. See e.g. U.S. Pat. Nos. 4,851,214, 5,016,568, 5,189,987 and 5,901,661. However, to achieve optimal adhering and uniformity (and thus effectiveness) of these odor control materials, applying them to the base material in liquid form is desirable. Unfortunately, applying liquids to a clumpable litter can cause premature clumping and/or adversely affect residual absorbency.
In a variety of contexts (e.g. fragrance applied to powdered detergent) liquids are applied to powders in a spraying process without significant clumping occurring. However, these formulations are not particularly designed to clump extremely easily in the presence of liquid.
Hence, a need exists for improved clumpable litters having odor control capability.